Various facilities routinely include tanks for storing liquid materials and other materials. For example, storage tanks are routinely used in tank farms and other storage facilities to store oil or other materials. As another example, oil tankers and other liquid transport vessels routinely include numerous tanks storing oil or other materials.
Often times, it is necessary or desirable to measure the level of material in a tank, such as during loading of material into the tank or unloading of material from the tank. Among other approaches, radar gauges and servo gauges have been used to measure the material level in a tank. A radar gauge typically transmits radar signals towards material in a tank and receives radar signals reflected off the surface of the material in the tank. A servo gauge typically raises and lowers a displacer located inside a tank, where the displacer's weight changes when submerged in the material.
On occasion, radar gauges, servo gauges, and other level-measuring gauges stop functioning properly. For example, the displacer of a servo gauge could become stuck within a tank. Similarly, pumps or other equipment could malfunction during the transfer of material into or out of a tank. These and other problems could allow volatile or other dangerous material to escape, resulting in environmental damage and injury or even death to nearby personnel. As a result, level-measuring gauges, pumps, and other equipment often include circuitry or other components for periodically testing the equipment or otherwise ensuring that the equipment is operating properly.